Protective system and radiant energy apparatus



Aug. 1; 1933. w. F. HEMLER PROTECTIVE SYSTEM AND RADIANT ENERGY APPARATUS 2 Sheets-Sheet 1 Filed Sept. 10, 1930 Aug. 1, 1933. w R HEMLER 1,920,861

PROTECTIVE SYSTEM AND RADIANT ENERGY APPARATUS Filed Sept. 10, 1950 2 Sheets-Sheet 2 VII/III! I Mg;

Patented Aug. 1, 1933 I .-1,9Zo,8fi1,

PROTECTIVE SYSTEM AND RADIANT EN- 'ERGY APPARATUS William F. Hemler, Washington; D.

Application September 10, 1930 7 Serial No. 481,051

10 Claims. (01. 250--34) The present invention relates to X-ray appaor behind the apparatus, there is little opporratus utilized for, radiography treatment and tunity' for anyone to contact directly with such fluoroscopy, and more particularly to means proleads as there are none exposed; but there is a viding safety to both operator and patient during greater chance that the metal parts of the appause thereof. ratus will themselves become charged as the 60 (1) In the present day apparatus it is jcusconductors are mounted in close proximity theretomary to ground the various metal portions of to (as distinguished'from radiographic and treatthe apparatus, such as the X-ray table, the tube ment apparatus wherein the high tension leads stand, etc. for the purpose of preventing injury are usually mounted an appreciable distance from from shock, should such apparatus accidentally the metal parts, but thetube is supported within become charged byhigh tension current in the easy reach of patient and operator above or in system. This is satisfactory in installations front of the table). Hence it is necessary, for the where the high tension leads are kept out of, utmost of safety, that the metal p b6 grounded. reach or concealed as in the conventional flua Such t a t e flu p apparatus i l5 oroscopic apparatus'but it so happens that in being used, and accordingly another object is to 7 most installations, and .particularly in the use of pr v a m ansfor autom l y grounding the radiographic apparatus th t th r r numsystem to earth when the fluoroscopic tube is her of necessarily exposed high tension wires,v char e. g. the conductors to and from the tube proper; Frequently, an X-ray, installation involves a and should any one accidentally come in concombination of radiographic, fluoroscopic and 75 tact with such exposed wire and at thesame treatment apparatusin orderto permit diagtime contact with a grounded metal portion of nosis as well as therapy; and fr m th foregothe apparatus, as is very likely to happen in the ins it will be seen that: it is necessary to decase of a patient who inadvertently'raises a hand earth the system when radiographic or treator is getting on or off of the table, or an operament methods are usedwhichrequire the presso tor who is changing tube terminals, injury would 1106 Of e p high te lines, and to earth follow, the current being carried from the conthe system when the fluroscope is use which ductor to the grounded metal through the pap m ts pla thev high tension lines out of tient or operator. probable human reach, the two portions of the (2) Most floors in X-ray rooms in modern firesystem being, of course, operated separately and proof buildings are of concrete construction. never simultaneously.

Such floors are excellent electrical conductors In order to avoid anypossible chance of forfor high tension currents and thus act as ungetfulness on the part of an operator, means controlled grounds to earth for metal equipment are provided whereby initiation of operation 01' 35 standing thereon. either phase of the system by meansof high (3) It is customary today to use a 110 volt tension switches automatically earths or destreet current from an ordinary house circuit to earths,- the apparatus dependent upon whether operate magnetic breakers in remote control the exposed conductors or the concealed conducswitches, magnetic trips of automatic plate tors are charged.

40 changers, insulated transformers and other low A featu e 01- the System described resides tension electrical devices in rooms where high the means for insulating the entire apparatus tension lines are exposed. g from earth by forming walls, floors and ceilings Such low tension street lines will ground high of a heat-proof material, impervious to Roentgen r tension charges to earth and constitute an unrays and incapable of conducting electricity.

controlled ground to earth for high tension Another feature of, the system is the use of charges. a, a one-one transformer or insulation transformer Accordingly, an object of the present invention of other suitable ratio to provide low tension is to provide means for completely and automaticircuits to light cystoscopic-lamps, drop lights,

cally de-earthing the metal apparatus and all to supply magnetic .trips for circuit breakers,

do persons approaching thereto when any exposed plate changers, etc.

conductor is charged with high tension current. A more complete disclosure of these and other In theuse of fluoroscopic systems wherein the objects of the invention will appear as the de- X-ray tube is usually mounted beneath the surscription proceeds, reference being had tothe acface of the table, and the high tension leads are companying drawings, in which like reference nuself contained, 1. e. concealed beneath the table merals designate like parts, and of which Fig.- 1 represents a diagrammatic showing in perspective of the apparatus; 1 f

Fig. 2 represents an elevation partly in section of the automatic switch for controlling the grounding or ungrounding of the apparatus while controlling'the high tension circuits; and

Fig. ,3 represents a detail perspective of a portion of. the switch.

In the drawings represents a conventional X ray table having side frames 11. Xway tube may be mounted on a separate, 111037- able standard, preferably, (for the purpose of insuring like potential of all metalobjectsin the room), the standard 12 is mounted directly on one of the side frames 11. The tube-13 is adjustably supported by the standard 12, and is .provided with electrodes 14 connected to high tension leads 15, which are mounted a suitable" distance above the table as, for example, by

brackets fixed to the ceiling, sumcient flexibility being permitted by conventional reels and flexible wire in the leadsfto the tube terminals Beneath the. table is located the housing 16.- for a fluoroscopic tube (notshown) and into whichhousing enter the hightension leads 17 therefor.

' A switch 18 (shown diagrammatically in Fig. 1) is-provided by means of which the high tension current is passed to the leads or 17, as desired, and a foot switch 19 is also provided by means of which theiremote control switch for operation of the apparatus for certain uses'as in iiuoroscopy is controlled.

Current from outside sources for purposes requiring exposed low tension wires which will ordinarily earth high tension charges is fed through leads" 20' to an oil insulated transformer 21 of 1-1 ratio, the secondary current from this transformer being thus insulated from earth and utilized for the operation-ofcystoscopic lamps, drop lights, remote control switches and various other low voltage lamps or apparatus.

- This current from outside sources is fed (1) to: the primary of the l-l transformer and (2) to main X-ray current line of the circuit breaker, and (3)- through a special armof the switch 18 or'a separate switch connection therewith for use-of various low voltage apparatus. Such apparatus may include a motor or motor driven tilt table (not'shown), or as stated above, various lamps-switches, etc. As pointed out hereinafter,

i purposes, and carried to a control cabinet for use as primary 10w tension circuit of the high tension transformer of the system.

.The purpose of the current entering through leadsi20i's solely'for the operation of apparatus 1 re'quiring'low voltage and to this end the secondary of the transformer 21 is carried through the circuit breaker 23, a magnetic switch or circuit 'breaker 'operator23a, thence to the foot switch 19 bymeans of which the magnetic switch operator is controlled. A circuit24 in parallel with the circuiti'through 23* may well operate'plate changers or other apparatus in an adjacent room.

-The- 'currentfrom leads 22 will pass through the: magnetically operated circuit breaker and connections-22a into the X-ray transformer.

While the An ideal layout comprises a combination radiographic and fluoroscopic room, such as illustrated in Fig. 1 of the drawings, and a separate room for pure radiographic and treatment work, with a control booth and suitable high tension switch and perhaps the main transformer room in between the two- The control booth and the room for radiographic diagnosisare not illustrated here but it is to be understood that suitable apparatus may be" located therein. The leads. 25 and 26 (Fig. 1) serve to connect the high tension secondary of the main X ray transformer with the sv itch-18; lead '24 carries de-earthed low tension cir'ouit'from the secondary of the 11 transformer to the transformer room.

The side walls and floors of such a laboratory will comprisean electrical insulating mediumwhere heretofore sheet lead and other conducting materials have been used. A plaster having in its composition barium sand and powdered barium and gypsum, to form a mediuinwhich is electric-shock proof, ray-proof and fire-proof, is an illustration of such medium and accordingly the walls and floor 27 will be so formed.

By using walls, floors and ceiling of this nature it will be seen-that all apparatus is insulated against accidental grounds, and furthermore the 1-1 transformer 21 "and the'circuit breaker 23 being of the oil insulated type, afford insulation between incoming street leads which might otherwise accidentally serve to ground the high tension chargesof the system. Theonly manner in which any connectionto earth is had in that part of the systemexposed to ordinary human reach, in the presenceof high tension lines as thus far described -will be. through the main leads from outside, whichsupplycurrent to theapparatus, and by the use of the oil transformer and oil circuit breaker, such grounding to earth through the low tension street line isprevented. 3

I A purposeful ground 28 to earth is provided and connected through the medium of water pipes or equivalent material embedded in the wall, and a connection therefrom is made to the switch 18.

A ground earthed connection 29 for the table 10 is formed by running a conductor to a terminal 30 of the switch 18. The standard 12 7 being mounted on or grounded tothe frame 11 of the table 10 is likewise earthed' through this same connection, and by use of a connection 31 from the switch 19 to the table l0, the earthing of table and all other metal equipment is obtained because all other conducting materials within the exposure room are permanently grounded to the frame of table 10 and frame 11 and thus-earthed or de-earthed simultaneously with frame 11. A baffle or protective partition is placed in front of the. table 10, or may be attached thereto, this for the purpose of preventing accidental contact with the high tension leads 17, underneath the table; it being understood, of course, that these leads may be suitably encased 'or embedded in the floor at such points as would otherwise be exposed adjacent to the table. 1

A casing 33 composed of non-conducting material is arranged between the switch and high tension terminals thereon, and the table 10. By passing the high tension leads from the switch through this casing suitable air insulation is provided, and similarly other leads such as the ground connection 29 or the conductor 24. may be passed as desired through this casing which in effect forms not only a protective enclosure, but an insulator for the high tension leads.

It will'thus be seen that a unit potential has been provided consisting of and secured by the interconnection of all metal apparatus and conducting materials in the rooms, exposed to probable human reach in the proximity of exposed high tension leads, for example, the table 10 with its metal frame 11, the standard 12 for the X-ray tube, and the foot switch 19, and if, for instance, a separate tube stand is used instead of one mounted on the frame 11, such stand is to be included as a part of the unit by firmly grounding same to the table frame by strong cable or in other suitable manner.

The one connection 29 thus serves for the entire unit, and consequently when this connection is completed through the switch 18, the entire apparatus is earthed. When, however, this connection is broken through the switch 18, the entire unit (of exposed conducting material) will be completely de-earthed, inasmuch as the floor and walls of the room are formed of efficient nonconducting or preferably high insulating material, so as to maintain an air distance which is suflicient insulation of the high tension voltages in use.

The switch 18 may be of any desirable construction suitable to the purpose, and is illustrated herein as comprising a series of longitudinally extending members 35, which serve to connect and space a series of frame members 36. Certain of these members 36 will mount terminals for certain lowvoltage lines, as illustrated in Fig. Lat 37, an illustration being the circuit including the primary 37a of a filament transformer for the X-ray tube, while others support terminal 39 for the line to ground the system to earth as already described, and others for the high tension circuits as illustrated at 38; all so arranged and constructed as to prevent the grounding'of the system to earth when exposed high tension lines are in use. Thus at least one of the members 36 will have a terminal 39 effective to establish a ground connection from the conductor 29, and terminal 30, the ground being, as stated above,

of any suitable nature as for example, a water pipe embedded in the wall 27.

By reference to Figs. 2 and 3, in which details of such a switch are illustrated, it will be noted that the switch comprises a modification of the usual high tension type commonly used; in this case a rock shaft 40 on. which are mounted switch arms 41; a pulley 42 at one end of the shaft is engaged by a control rope 43 which serves as a means to rock the shaft in one direction or another, thereby positioning the switch arms 41 upper terminal of the frame with the terminal at the rear. Fig. 2 illustrates the frame member at the right of the switch, as shown in Fig. l.

- In the frame member to which the ground terminals are connected, the switch arm 41 when in its lower position will connect terminal 30 directly to terminal 39, and when in its upper position will engage no terminal, but will project free into the air.

A suitable arrangement of switch arms is to be used for the low voltage lines, the terminals for which will be mounted on other necessary frames, or on an extension frame or interconnected by cords or cables to other high tension switches as that between the radiographictreatment and fluoroscopic rooms so that all metal apparatus in any exposure room connected with the system will necessarily be deearthed except when the high tension circuit is connected with self contained or non-exposed conductors. It will be obvious that the number of frames, switch arms, and terminals and interconnections of pull cords or arms between switches may be varied as desired to accommodate varying conditions; the main essential of this arrangement being that as the trip cord 43 is pulled in one direction and a circuit established through exposed high tension lines 15, all ground connections to earth will simultaneously be broken, leaving any metal apparatus situated within human reach in any room which may be used completely insulated from .the earth; and when the cord is pulled to establish a high tension circuit in the non-exposed or self contained (fluoroscopic) lines 17, all metal apparatus of such fluoroscopic unit will be earthed as a unit through the terminals 30 and 39 (the several elements of the unit having been interconnected by being grounded to the table), it being clear that as the any one set of high tension lines is energized, all others will be de-energized. The high tension switch over the control booth may thus be made to operate as a master high tension and ground switch controlling all high tension and ground circuits.

The entire apparatus is electrically insulated from the earth at all times, insofar as ordinary conditions are concerned, due to the construction of walls, floors and ceiling, and the use of the insulation transformer heretofore mentioned; the only possible connection to earth being through the ground 28 via line 29 and terminals 30-39, and when the connection be tween 30 and 39 is broken, all other possible circuits for high tension currents to earth are likewise broken and there is no possibility or likelihood of accidentally grounding or earthing any part of the apparatus. All leads and conductors, insofar as is possible, are located outof reach of the operator and patient, those through the wall being normally above the average persons reach, those not embedded in the wall being encased by suitable insulation, preferably by providing air distance. The ends of conductors 15 adjacent the tube are necessarily exposed, and when current is passing through these leads, there is no part of the apparatus which can be grounded. The leads 17 are selfcontained, concealed and protected and all metal parts are automatically grounded at such time as these leads are electrified.

The reason for these conditions will be apparent from the foregoing, viz. when there is a greater chance of the patient or operator con posed, and there is practically no chance of any person coming in contact therewith; and there are then greater chances of accidental charging of the metal apparatus (because of the proximity thereto of such leads), earthing of such ap- I paratus is then necessary.

Should there be a failure in the ground line'28,

29, 30, 39 there is still an element of safety pro vided by the complete insulation of all apparatus from other grounds, even such grounds as might accidentally be provided through the street primary wires 20 and 22, because in this system such lines are oil insulated from the secondary or insulated low tension circuit which are exposed to high tension conductors, such insulation being sufiicient to withstand accidental high tension charges.

It is understood that if other high tension switches or other low tension arms are attached to such switches, they shall be so interconnected as to act simultaneously in order that all grounds to earth shall be broken when exposed high tension leads are charged in any exposure room.

It will be understood .that the advantages of the above described system apply regardless of whether a combined 'radiographic or fluoroscopic apparatus is used, or whether either is used by itself. The insulation of the walls and floors, offers an increased measure of safety and acts to completely insulate either phase of the system. If, however, either part of the system forms the total installation, then of course it may not be necessary to utilize. the switch exactly as described. This insulation of floors and Walls may be secured:

(l) By use of barium sand, gypsum, plaster already mentioned as radiation barrier, or

(2) By placing of necessary sheet lead at a dis-' tance of preferably 12 inches or a distance at least equal to the spark gap capacity of the transformer in use, below the normal floor level, said distance to be maintained by hollow clay tile, covered by and cemented together by gypsum and other suitable non-conducting cement substances. Having thus described my invention what I claim as new and desire to secure by'Letters Patent ofthe United States, is:--- I 1. In an apparatus of the type described, the combination with metal portions therein, of means to ground said metal portions, and a plurality of X-ray tubes, means to supply high tension current to said tubes including exposed electric conductors to one of tubes, unexposed conductors to the other of said tubes, said conductors being located in proximity to said metal portions, and means to conn ct said metal portions to earth when said un osed conductors are electrified, and to disconnect said metal portions from earth when said exposed conductors are electrified.

2. In an apparatus of the type described, the combination with metal 7 portions therein, of means to ground said metal portions, and a plurality of X-ray tubes, means to supply high tension current to said tubes including exposed electric conductors to one of said tubes, unexposed conductors to the other of said tubes, said conductors being located in proximity to said metal portions, and means including a switch effective to establish simultaneously a circuit through said unexposed conductors when in one position and through said exposed conductors when in another position, and to connect said metal portions to earth through said grounding means, when said unexposed conductors are electrified and to disconnect said metal portions from earth whe saidexposed conductors are electrified.

3. Inan apparatus of the'type described, the combination with -metal portions therein, of means to ground said metal portions, and an X-ray tube, means to supply high tension current thereto including exposed electric conductors therefor, adjacent certain of said metal portions, and means including a switch effective to establish a circuit through said exposed conductors and simultaneously to disconnect said metal por-- tions from ground when saidexposed conductors are electrified, said portions being connected to a. terminal of said switch, and said switch having a terminal connected to earth, and an arm effective to complete a circuit through said, terminals.

4. In an apparatus of the type described, the combination with metal portions therein, of means to ground said metal portions, and a plurality of X-ray tubes, means to supply high tension current to said tubes including exposed electric conductors to one of said tubes, unexposed conductors to the other of said tubes, said conductors being located in proximity to said metal portions, and means including a switch effective to establish a circuit through said unexposed conductors when in one position and through said exposed conductors when in another position, and simultaneously to connect said metal portions to earth when said unexposed conductors are electrified and to disconnect said metal portions from earth when said exposed conductors are electrified, said portions being connected to a terminal of said switch, and said switch having a terminal connected to earth, and an arm effective to complete a circuit through said terminals.

5.- In an apparatus of the type described, the combination with a plurality of. metal portions therein, means to ground said metal portions,

and an X-ray tube, means to supply high tension current thereto including exposed electric conductors therefor, adjacent certain'of said metal portions, means to electrically connect said metal portions to each other thereby to form a unit, means to disconnect said unit from earth when said exposed conductors are electrified, including a switch effective to disconnect said unit from earth and also effective to simultaneously establish a circuitthrough said exposed conductors.

6. In an apparatus of the class described, having metal portions forming a part thereof, and incoming leads from a source of low voltage current, the combination of an oil insulated trans-- former to which said leads are electrically con-. nected, an oil insulated circuit breaker electrically connected to said transformer, a plurality of X-ray tubes, means to supply high tension current to said tubes, including an exposed high tension conductor to one of said tubes, an un exposed high tension conductor .to the other of said tubes, said conductors being located in proximity to said metal portions, and means to ground said metal portions when said unexposed conductor is electrified, and to disconnect said metal portions from earth when said exposed conductor is'electrified.

'7. In an apparatus of the class described, having metal portions forming a part thereof, and incoming leads from a source of low Voltage current, the combination of an oil insulated transformer to which said leads are electrically connected, an .oil insulated circuit breaker electrically connected to said transformer, an X-ray' tube, means to supply high tension current thereto including an exposed high tension conductor in proximity to said metal portions and connected in circuit with said circuit breaker, means con- .iected to said transformer for energizing said breaker, and means including a switch effective to establish a circuit through said exposed conductor and to disconnect said metal portions from earth when said exposed conductor is electrified.

8. In an apparatus of the class described havno v ing metal portions forming a part thereof, and incoming leads from a source of low voltage current, the combination of an oil insulated transformer to which said leads are electrically connected, an oil insulated circuit breaker electrically connected to said transformer, a plurality of X-ray tubes, means to supply high tension current to said tubes, including an exposed high tension conductor to one of said tubes, an unexposed high tension conductor to the other of said tubes, said conductors being located in proximity to said metal portions, and means, including a switch efiective to establish a circuit through said unexposed conductor when in one position, and through said exposed conductor when in another position, to earth said metal portions when said unexposed conductor is electrified and to disconnect said metal portions from earth when said exposed conductor is electrified.

9. In a system of the type described, the combination with conductors leading to a plurality of low voltage electrical devices having metal portions, and a high tension electrical apparatus having metal portions, a source of low voltage current, a transformer, incoming leads connecting said source to said transformer, a plurality of X-ray tubes, means to supply high tension current to said tubes, including an exposed high tension conductor to one of said tubes, an unexposed high tension conductor, to the other of said tubes, said conductors being located in proximity to said metal portions, and a switch effective to simultaneously connect said low voltage conductors directly to said source when such unexposed high tension conductors are electrified and to disconnect said low voltage conductors from said source when such unexposed high tension conductors are electrified.

10. In an X-ray, radio-graphic, fluoroscopic system of the type described, the combination of a low tension circuit with a plurality of high tension circuits, one of said high tension circuits being exposed, and another being unexposed, insulating means between said high and low circuits effective to prevent electrification of said low tension circuit by accidental high tension charges from said high tension circuits, a metal electrical device arranged in said low tension circuit and located in proximity to said high tension circuits, and means to connect said device to ground when said unexposed high tension circuit is electrified and to disconnect said devicefrom glOLlIld when said exposed high tension circuits are electrified.

WILLIAM F. HEMLER. 

